   (fn [state]
     (if (:gtm state)
       (let [pos (:position (:gtm state))
-            instr-map (get-in state [:gtm :tapes 0 pos])]
+            instr-map (get-in state [:gtm :tracks 0 pos])]
         (if instr-map
           (trace 'gtm_read_all
                  (push-item (:instruction instr-map) :code state)



;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Instructions for moving the read/write head.

(define-registered ;; move head to the left
  gtm_left

      (trace 'gtm_erase
             (let [pos (:position (:gtm state))]
               (assoc-in state
                         [:gtm :tracks 0]
                         (dissoc (get-in state [:gtm :tracks 0]) pos))))
      state)))

(define-registered ;; push all components to stacks
